1. Field of the Invention
The present invention relates to a coupling apparatus for coupling a blade protector to a tool body of a gardening tool.
2. Description of the Related Art
In general, gardening tools, in particular, brush cutters or grass cutters used outdoors for cutting grasses or the like, have a support rod and a rotary blade mounted to a front end of the support rod. The support rod has a suitable length for operation by a user who operates standing-up. A handle extends laterally in right and left directions from a middle portion of the support rod and can be grasped by the user. A drive device for rotatably driving the blade is mounted to the rear side of the support rod. An engine-type drive device or a motor-type drive device has been used as the drive device. A disk-type rotary cutter with tips secured to the periphery may be used as the cutting blade. Alternatively, vinyl cords may be used as the cutting blade.
The cutting blade is supported at the front end of the support rod via a gear head portion. A protector is coupled to the rear side (i.e., the side of user) of the cutting blade for preventing cut grasses or ground pebbles from bouncing toward the user. Normally, the protector has a size capable of covering about one third of the entire circumference of the rotary blade to mainly cover the side of the user. A repairer sometime may remove the protector for the maintenance or repair service of the gear head or other. The protector is coupled to the support rod by a coupling apparatus. For example, the coupling apparatus may include a fixing screw as a coupling member. The fixing screw is tightened for fixedly coupling the protector to the support rod. In this case, the protector can be removed from the support rod by loosening and removing the fixing screw. The coupling apparatus using the fixing screw as the coupling member is disclosed, for example, in Japanese Laid-Open Utility Model Publication No. 7-7330.
However, if the fixing screw has been removed from the protector, a troublesome work is required for setting the fixing screw again when the protector is mounted again after the maintenance work or the repair service. In addition, the fixing screw may be lost.
Therefore, there is a need in the art for preventing removal of a coupling member that couples a blade protector to a cutting device.